Makkuni, Unni Kannan.

In this thesis, a comparative evaluation of some residue generation methods used for model based failure detection techniques is made. Residues are differences between the actual plant outputs and the outputs of a mathematical model describing the plant. Under a no-fail condition and in the absence of noise, the residues are zero. When a failure occurs, the residues will be non zero and the nature of the residues depend on the residue generation method and the system input. The resulting residues are statistically analyzed to isolate the nature of the failure(s). Three methods for residue generation namely, parity relations, parameter estimation and estimation by the Kalman filter are discussed. A mathematical analysis for the basis of choosing a statistical test which depends on the system input is also presented.